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Zinc Deficiency

Zincum Deficientia

Basic Details

Description

Nutrient Info

Identify

Seasonal Calendar

Treatment

FAQs

How to Identify Zinc Deficiency on Mango

Zinc Deficiency identification guide illustration

Visible Symptoms

Leaves emerge extremely small, narrow, and clustered in a tight, rosette-like bundle at shoot tips (hence 'Little Leaf'). Leaves are thin and display interveinal chlorosis.

Key Identification Checklist for Mango Zinc Deficiency ("Little Leaf" Disorder): 1. Drastic Leaf Size Reduction ("Little Leaf"): Newly emerging leaves on vegetative growth flushes are drastically reduced in size, often measuring only 10% to 25% of normal length and breadth. 2. Rosetting & Terminal Bunches: Branch internodes fail to elongate due to auxin (IAA) synthesis failure. Multiple tiny, narrow, lanceolate leaves cluster together at the shoot tip, creating a dense, compact brush-like rosette or "witches' broom" appearance. 3. Thick, Leathery Texture with Upward Cupping: Affected leaves become abnormally thick, brittle, and leathery. Leaf margins curl upward with faint interveinal chlorotic mottling between the main green veins. 4. Stunted Panicles & Hermaphrodite Flower Failure: Flower panicles emerging from zinc-starved terminal shoots are dwarfed, compact, and produce almost exclusively sterile male flowers, leading to complete fruit set failure on affected branches.

About Zinc Deficiency

NameZinc Deficiency

Description

Zinc deficiency is a major physiological disorder in mango trees, particularly in sandy, alkaline, or over-limed soils. It severely limits auxin hormone production, stopping shoot elongation.

TypeDeficiency

Severity Level Moderate

Nutrient Role & Deficiency Cause

Affected Growth Stages

Vegetative

Why It Happens

Zinc deficiency is a major physiological disorder in mango trees, particularly in sandy, alkaline, or over-limed soils. It severely limits auxin hormone production, stopping shoot elongation.

Also Known AsLittle leaf of mango, rosetting

Seasonal Outbreak Calendar

Outbreak risk and activity timeline for Zinc Deficiency based on seasonal climate patterns:

Active Window:February - July

Peak Outbreak:March - June

Critical Crop Stage:Spring and summer growth flushes

JanLow Risk

FebModerate

MarPeak Risk

AprPeak Risk

MayPeak Risk

JunPeak Risk

JulModerate

AugLow Risk

SepLow Risk

OctLow Risk

NovLow Risk

DecLow Risk

Low Outbreak Risk

Active / Moderate Risk

High Risk / Peak Outbreak

Want to see this disease and others mapped across other regions? View Global Outbreak Calendar

Treatment & Correction Guide

Natural & Organic Methods

Zinc-Enriched Farmyard Manure Tree Basin Application

40–50 kg well-decomposed FYM pre-incubated with 250 g Zinc Sulfate per mature tree Applied annually in the tree drip line basin (2–3 meters from trunk) after post-harvest pruning Protects zinc from soil fixation and enhances mycorrhizal root absorption over 2–3 months

Tree Drip Line Biomass Mulching & Organic Manuring

4–6 inch layer of dry leaves and pruned twigs in the active canopy perimeter Applied at start of dry winter period (October–November) Conserves soil moisture and fosters native mycorrhizal fungi to solubilize micro-nutrients

VAM (Mycorrhizal Biofertilizer) Soil Trench Inoculation

100 g VAM inoculum per tree incorporated in the feeder root zone Single application at the onset of monsoon showers Greatly expands root surface area for zinc absorption in calcareous soils

Chemical & Professional Control

Foliar Zinc Sulfate (ZnSO4 · 7H2O, 21% Zn) Neutralized with Lime

5 g Zinc Sulfate + 2.5 g Slaked Lime per Liter water (0.5% ZnSO4 + 0.25% lime; 1 kg ZnSO4 + 500g lime in 200L) 2 sprays: 1st spray on new vegetative flush (July–August), 2nd spray before flowering (October–November) Rapid leaf expansion and restoration of normal shoot elongation in 10–14 days

Chelated Zinc (Zn-EDTA 12%) Foliar Application

1.0–1.5 g per Liter water (200–300 g in 200L) Spray during active flush expansion in early morning hours Fastest cuticular absorption without any risk of phytotoxic leaf scorching

Soil Application of Zinc Sulfate (Sandy / Acidic Soils Only)

200–250 g Zinc Sulfate per mature bearing tree broadcast in drip line Once every 2 years in post-monsoon (ineffective in high-pH calcareous soils) Gradual replenishment of orchard soil zinc pool

Frequently Asked Questions

Why is zinc deficiency in mango known as 'Little Leaf' disorder?

Zinc is the essential co-factor for the synthesis of tryptophan, the biochemical precursor of indole-3-acetic acid (IAA / auxin). Without auxin, cell expansion in developing leaf buds is blocked, causing new leaves to emerge tiny, narrow, and stunted.

Why do multiple leaves form a compact 'rosette' at the tip of the mango shoot?

Auxin regulates internodal stem elongation. When zinc is deficient, the internodes between successive leaf nodes fail to lengthen, packing 10–20 tiny leaves directly against one another into a tight, brush-like rosette.

Why is foliar spraying far more effective than soil application of zinc in mango orchards?

Mature mango trees have deep, extensive root systems, and orchard soils are frequently alkaline or calcareous (pH > 7.5), which chemically locks soil-applied zinc as insoluble zinc carbonate. Foliar sprays deliver zinc directly into active photosynthetic leaf tissue through stomata.

Why must slaked lime always be added to zinc sulfate spray on mango trees?

Technical zinc sulfate is acidic (pH ~4.5). Unneutralized zinc sulfate causes severe chemical scorch, marginal burning, and premature drop of delicate young mango leaves. Adding half the weight of slaked lime (2.5 g lime per 5 g ZnSO4) neutralizes the solution to a safe pH of 6.5–7.0.

How does zinc deficiency affect mango flowering, hermaphrodite flower ratio, and fruit set?

Terminal shoots suffering from zinc starvation produce deformed, stunted panicles with an abnormally low percentage of hermaphrodite (bisexual) flowers. Over 95% of flowers emerge as male or malformed, leading to near-total failure of fruit set on deficient branches.

Remedy Disclaimer & Safety Notice

This disease guide is for educational screening purposes only. Pathogen behavior, severity, and host susceptibility can vary dramatically based on seed variety, weather conditions, and regional microclimates. Chemical pesticides and organic treatments are subject to strict regional environmental regulations and registration mandates. Please verify all chemical registrations and review manufacturer safety labels carefully with local certified agronomists or agricultural extension service offices before applying.

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